<template>
  <div class="app-container">
    <el-input v-model="filterText" placeholder="Filter keyword" style="margin-bottom:30px;"/>

    <el-tree
      ref="tree2"
      :data="data2"
      :props="defaultProps"
      :filter-node-method="filterNode"
      class="filter-tree"
      default-expand-all
    />

  </div>
</template>

<script>
    export default {

        data() {
            return {
                filterText: '',
                data2: [
                    {
                        id: 1,
                        label: 'Level one 1',
                        children: [{
                            id: 4,
                            label: 'Level two 1-1',
                            children: [{
                                id: 9,
                                label: 'Level three 1-1-1'
                            }, {
                                id: 10,
                                label: 'Level three 1-1-2'
                            }]
                        }]
                    }, {
                        id: 2,
                        label: 'Level one 2',
                        children: [{
                            id: 5,
                            label: 'Level two 2-1'
                        }, {
                            id: 6,
                            label: 'Level two 2-2'
                        }]
                    }, {
                        id: 3,
                        label: 'Level one 3',
                        children: [{
                            id: 7,
                            label: 'Level two 3-1'
                        }, {
                            id: 8,
                            label: 'Level two 3-2'
                        }]
                    }
                ],
                defaultProps: {
                    children: 'children',
                    label: 'label'
                }
            }
        },
        watch: {
            filterText(val) {
                this.$refs.tree2.filter(val)
            }
        },

        methods: {
            filterNode(value, data) {
                if (!value) return true
                return data.label.indexOf(value) !== -1
            }
        }
    }
</script>

